DE3888176T2 - Latent crimped yarn, fabric web made from this yarn and process for producing this yarn. - Google Patents

Description

The present invention relates to a crimped yarn which is produced by passing a running yarn into a texturing zone where it is subjected to a vortex current created by a pressurized fluid to form open and closed loops on its surface. More particularly, the present invention relates to a latently crimped yarn and a method of producing the same in which the yarn is first provided with open and closed loops, the latent loops then becoming apparent after the latently crimped yarn has been woven into a fabric, and to a method of producing such a fabric.

The present invention also relates to a high-density fabric made of latently crimped yarn having a spun-like feel (hereinafter referred to as "spun-like" fabric).

Different processes for producing bulky yarn are known in which the bulk is created by shrink yarns that have filaments with different shrinkage properties along their length and/or different shrinkage properties from each other.

US-A-3273328 describes a process for producing a bulky yarn in which a crimped multifilament yarn component is stabilised against stretching by a multifilament yarn component in which the filaments are straight. The respective components are interlaced by an air jet either before or after the crimping of one component. The crimped component can be created by filaments which have different thermal shrinkage properties from those of the straight component and which can shrink differently during a crimping operation following braiding. GB-A-1590207 describes the manufacture of a bulky yarn suitable for knitwear. A drawn yarn having a A single multifilament yarn component or a blended drawn yarn comprising two different multifilament yarn components, each having different thermal shrinkage properties, is passed over a random heat treating needle, then to a movable interlacing device and then over a tension control roller which provides a tension of the yarn on the heated needle which is less than the thermal shrinkage stress on the yarn, thus loosening individual filaments and creating a contact time at the needle which is short enough so that heat from the needle cannot be conducted evenly to all parts of the yarn. This produces filaments which have thermal shrinkage values which differ along the length of each fibre and from one fibre to another for a given cross-section. It also creates randomly arranged loosened, curved sections. After the filaments have been interwoven, they are fed at an advance of at least 10% to an air jet texturing device in which a fluid turbulent flow causes randomly twisted sections which form loops after the yarn is released.

GB-A-2048329 discloses a bulkable filament yarn having filaments which are substantially straight but have a number of interlaced sections along their length. The group of filaments between each pair of interlaced sections has mixed, variable boil-off shrinkage characteristics both between the filaments and within each filament. The yarn is made by feeding a yarn to a jet of turbulent fluid at a constant overfeed ratio, whereby the yarn is provided with periodically interlaced sections between arch-like, i.e. open, crimped sections, whilst avoiding the formation of closed loops. The resulting yarn is heat treated under a tension which is insufficient to remove the loops by stretching. The heat treatment causes the loops to shrink without constraint and to undergo increased heat treatment compared with the straight sections, thereby reducing the difference in Boil-off shrinkage is increased between the crimped and straight sections.

DE-A-1804525 describes the production of a bulky yarn in which two multifilament yarn components with low and high shrinkage are interlaced by air jet entanglement. The yarn component with high shrinkage is fed to the air jet zone under overfeed, which provides the yarn with arches, with the yarn component with the highest shrinkage having the largest arches. The material is then shrunk by heating and then false twist crimped.

Consequently, different crimped yarns are known and have proven to be valuable, in which the respective partial filaments of a multifilament yarn are provided with many fine open and closed loops, since such crimped yarn has the property of making a fabric appear voluminous and giving it a certain stiffness.

However, many operational problems arise when these crimped yarns are used in the weaving process to produce a fabric; for example, the yarn gets caught on abrasive contact points of a guide or a tensioner, causing abnormal tension in the yarn. This leads to the thread breaking or its properties being destroyed.

There are many types of blown crimp yarns in which a large number of fine open and closed loops are located on the respective component filaments of a multifilament yarn in order to produce a spun-fiber-like fabric when using multifilament yarns, and many proposals have been made for producing such a yarn because these yarns can produce a fabric that has a voluminous feel and a certain stiffness.

These types of yarn have the significant disadvantage that the loops are eliminated when a strong tension is applied, which exceeds the required tension level, and consequently, the voluminous property imparted to the yarn is lost. Moreover, the voluminous property disappears because the open and closed loops on the surface of the yarn are formed only by entanglement between the component filaments.

Fabrics are known that have a quality similar to that of spun fibers and a high density. This fabric is suitable for a coat or for outerwear for sports, for which waterproof or windproof properties are particularly required. Thus, JP-A-57-117647 proposes, as a fabric for such a purpose, a high-density fabric using synthetic two-component multifilament yarns having divisible or separable filament components, while JP-A-59-204941 and JP-A-60-394385 describe fabrics which are waterproof, moisture-permeable and water-repellent, which are produced by a process in which a high-density fabric is first woven using a multifilament blend yarn comprising a multifilament yarn as a high-shrinkage component and a multifilament yarn consisting of ultrafine filaments as a low-shrinkage component, and the fabric is then subjected to a water-repellent treatment.

These fabrics are made waterproof and moisture-permeable by limiting the spaces between the filaments to the order of microns by arranging the filaments in such a way that the number of filaments per unit area of the high-density fabric is set to an extreme upper limit.

Accordingly, in constructing such a fabric, the density of the filaments is increased in such a way that they are arranged as parallel to each other as possible. This fabric has a greasy feel due to the ultra-fine synthetic filaments and in this respect has the disadvantage that, from an optical point of view, it does not have any advantageous natural unevenness compared to a fabric made from spun yarns.

Japanese Patent Publication 61-40778 discloses a method for producing a napped fabric using an interlaced and mixed multifilament yarn having a two-layer structure in which a filament yarn having a high shrinkage ratio is used as a core yarn, and ultrafine fibers wound around the core yarn are used as a sheath yarn. A fabric woven or knitted from this yarn is napped.

Generally speaking, the above-mentioned crimped yarn is in many cases used as a weft yarn when a spun-like fabric is made therefrom, due to the above-mentioned problems which particularly occur when crimped yarns are used as warp yarns.

However, if a high-density fabric is to be made from multifilament yarns, it is not enough to use this crimped yarn only as its weft yarn; this crimped yarn should also be used as a warp yarn.

However, other disadvantages arise when using such a crimped yarn as a warp yarn of a fabric; for example, the density of the warp yarn must be extremely coarse due to the entanglement of the crimped yarns with each other on a weaving machine, which leads to the problem of lowered shedding ability during weaving as well as to the operational problems described above.

Many attempts have been made to solve these problems, such as refining the denier of the sheath yarn filaments, but these require the use of several types of attachments to collect the crimped yarn from a yarn carrier.

Even if an additional device is used, the density of the warp yarn is limited and consequently a fabric with a high warp yarn density cannot be produced.

Furthermore, in order to achieve satisfactory yarn take-up by a yarn carrier or satisfactory freedom of yarn passage through a weaving or knitting station or through a station located before or after such a weaving or knitting process in which a processing operation (such as yarn or fabric processing) takes place, it is normally necessary either to completely eliminate the loops or to provide the yarn with small loops only at a low density in such a way that the difference in yarn length between the respective component filaments of the yarn is kept extremely small. Consequently, a fabric cannot be produced whose surface is pleasant to the touch.

Therefore, at present, no crimped yarn can be used as a warp yarn to produce a fabric with a relatively high yarn density.

It is well known in the art that the number of loops and their size in a conventionally crimped yarn are rarely changed or slightly increased even if such a crimped yarn is subjected to a hot water treatment followed by free tension, and if such a crimped yarn were used as a warp yarn, it would be impossible to produce a fabric having a high density and a pleasant spun feel.

In order to produce a spun-fiber-like fabric with a high yarn density, a crimped yarn must be created that can be used as a warp yarn.

The object of the present invention is to eliminate the above-mentioned technical disadvantages and to create a new type of latently crimped yarns which can also be used as warp yarns of a high-density fabric, as well as a process for their production.

More specifically, the present invention is intended to provide a latently crimped yarn with which the take-up of the yarn carrier (the difficulties encountered here being a disadvantage associated with conventional crimped yarns as described above), whereby the yarn can be unwound from the yarn carrier at a high yarn speed and at the same time improve the conditions of a weaving process or other yarn or fabric processing process which take place before or after the weaving process. The latently crimped yarn can also be used as a warp yarn to produce a fabric having a high density weave structure and which is further suitable for producing a spun-fiber-like fabric the final product of which has a very pleasant feel without being subjected to special treatment such as the incorporation of nubs.

Furthermore, it is an object of the invention to create a spun fiber-like fabric with high density from this latently crimped yarn and a method for its production.

According to a first aspect of the present invention there is provided a method of producing a crimped blended yarn comprising simultaneously feeding at least first and second synthetic multifilament yarns to a texturing zone in which a vortex current flows, thereby producing a multifilament blended yarn having open and closed loops on the surface thereof, which is then stretched, thereby eliminating or attenuating (i.e. reducing the size of) said open and closed loops, wherein said first synthetic multifilament yarn has a higher shrinkage ratio in water than said second synthetic multifilament yarn. According to a second aspect the invention provides a high density fabric which:

(a) Warp yarns comprising a mixed multifilament blend yarn having open and closed loops on the surface thereof according to claim 1, wherein the cover factor (CF) of the warp yarns is given by the equation CF = n , where n is the yarn density (warp threads/inch) and d is the yarn denier or by the equation CF = 7.62 nSI , where nSI is the yarn density (warp threads/cm), more than 1100; and

(b) weft yarns includes.

Such a fabric can be a mixed fabric that:

(a) warp yarns or weft yarns comprising shrinkable multifilament blend yarns, said yarns having open and closed loops on their surface and comprising at least one synthetic multifilament yarn according to claim 1 and

(b) weft yarns or warp yarns comprising spun yarns;

wherein the total coverage factor of said warp or weft yarn, as defined above, is 2000 to 3500.

According to a third aspect, the invention provides a method of making a woven fabric having a spun-like feel and resembling a fabric made from super long cotton fibers, wherein the fabric is woven from blended multifilament blend yarns made from synthetic multifilament yarn components and having a total denier of less than 10 tex (90d), the blend yarn being made from a filament "a" having a shrinkage ratio in hot water of more than 12%, a denier of a component filament thereof being more than 0.17 tex (1.5d) and the total denier thereof being less than 6.67 tex (60d), and a filament "b" having a shrinkage ratio in hot water of less than 10%, a denier of a component filament thereof being less than 0.11 tex (1.0d) and the total denier thereof being less than 6.67 tex (60 d), the mixed yarn being further characterized in that it has, before shrinking, more than 300 warp threads/m of loops A, more than 50 warp threads/m of loops B and less than 10 warp threads/m of loops C, each loop A, loop B and loop C being defined below, and after weaving, shrinking of the fabric is carried out in order to obtain a differential shrinkage between filament "a" and filament "b" resulting in the protrusion of the open and closed loops of the filament "b" on the surface of the web, each loop A, loop B and loop C being defined in such a way that, when each loop is measured at a yarn speed of 50 m/min and a yarn running tension of 0.1 g/d (0.0108 cN/tex) with a photoelectric fuzz measuring device by which the number of loops of a yarn passed through is counted, a loop which projects beyond the yarn surface by more than 0.15 mm is referred to as loop A, a loop which projects beyond the yarn surface by more than 0.35 mm is referred to as loop B, and a loop which projects beyond the yarn surface by more than 0.6 mm is referred to as loop c.

According to a fourth aspect, the present invention provides a crimped blend yarn having open and closed loops on its surface, wherein the crimped blend yarn

at least one synthetic multifilament yarn component with a high shrinkage ratio and

at least one synthetic multifilament component with a low shrinkage ratio,

the shrinkage ratio of the filaments of the synthetic multifilament yarn component with a high shrinkage ratio in hot water is more than 10% and

the difference in shrinkage ratio between that of the filaments of the synthetic multifilament yarn component with a high shrinkage ratio and that of the filaments of the synthetic multifilament yarn component with a low shrinkage ratio in hot water is more than 5%,

wherein the crimped blended yarn is such that its total number and size of open and closed loops can be increased by thermal treatment of the yarn in the tension-free state,

each loop is classified as a Class A, B or C loop in terms of its projection height, the number of loops above a given height being measured at a yarn speed of 50 m/min and a yarn tension of 0.1 g/d (0.0108 cN/tex), where

Class A loops are loops that protrude above the yarn surface by more than 0.15 mm,

Class B loops are loops that protrude above the yarn surface by more than 0.35 mm, and

Class C loops are loops that protrude more than 0.6 mm above the yarn surface,

the crimped blended yarn on its surface before heat treatment

more than 300 warp threads/m of class A loops,

more than 50 warp threads/m of class B loops and

has less than 10 warp threads/m of class C loops,

the number of loops, measured after thermal treatment with hot water at 98ºC for 10 minutes in a tension-free state and subsequent drying, is such that

the number of loops of class B is more than at least 1,5 times that of the crimped yarn before heat treatment, and

the number of loops in class C is more than 50 warp threads/m.

The embodiments of the invention will now be described with reference to the accompanying drawings, in which:

Fig. 1 is a schematic representation of an embodiment of a process for producing a latently crimped yarn of the present invention;

Fig. 2 shows a graphical representation of the results obtained in Examples 1 and 2 of the embodiment of the invention described below;

Figure 3 is a cross-sectional view of a filament having a flat cross-sectional shape as used in a high density fabric according to the invention;

Fig. 4 shows a crimped yarn produced by a vortex flow of compressed air as obtained in Example 5;

Fig. 5 shows a latently crimped yarn according to the invention obtained by stretching the crimped yarn shown in Fig. 4;

Fig. 6 shows a crimped yarn produced in the tension-free state by heat treating the crimped yarn shown in Fig. 4 with hot water at 98°C; and

Fig. 7 shows a crimped yarn according to the invention after crimped loops have been developed on its surface by heat treating the latently crimped yarn shown in Fig. 5 with hot water at 98°C in a tension-free state.

In order to achieve the above-mentioned objects of the present invention, use is made of a latently crimped yarn which is a mixed multifilament blend yarn comprising at least two synthetic multifilament yarns having different thermal shrinkage and having fine, i.e. small, open loops and fine closed loops on its surface. By thermally treating the multifilament blend yarn in boiling water, the total number of closed and open loops and their size can be increased in the yarn compared to those present in the multifilament yarn before the heat treatment.

Hereinafter, a "closed" loop means a loop in which the root is closed as indicated by X in Fig. 5, and an "open" loop means a loop in which the root is opened as indicated by Y in Fig. 5. Furthermore, in the yarn of the present invention, the crimped yarn is characterized in that, in accordance with the classification of loops A, B, C as defined below, the total number of both open and closed loops present on the surface of the latently crimped yarn before heat treatment such as tension-free hot water treatment, and the yarn is in, for example, a strand, such that there are more than 300 warp ends/m of loops A, more than 50 warp ends/m of loops B, and less than 10 warp ends/m of loops C.

In classifying the loops, their projection height and number are measured with a yarn running at a speed of 50 m/min and a yarn running tension of 0.1 g/d (0.0108 cN/tex) using a photoelectric fray measuring device (e.g., a fray counter sold under the name "Toray Fray Counter" from Toray Industries, Inc.) that counts the number of loops passing through. A loop that projects beyond the yarn surface by more than 0.15 mm is defined as loop A, a loop that projects beyond the yarn surface by more than 0.35 mm is defined as loop B, and a loop that projects beyond the yarn surface by more than 0.6 mm is defined as loop C.

In addition, the latently crimped yarn is characterized in that a strong looping force remains therein. Note that the crimped yarn primarily has a looping force by which the number of loops 3 is increased by more than 1.5 times that of the yarn and the number of loops C is increased to more than 50 warp ends/m after the yarn is subjected to heat treatment with hot water at 98ºC for 10 minutes in a non-shrinking state and then dried.

A latently crimped yarn according to the invention will now be explained in more detail.

The latently crimped yarn of the present invention is a blended yarn basically comprising a multifilament yarn component having a high shrinkage ratio and a multifilament yarn component having a low shrinkage ratio, wherein in the latently crimped yarn, both multifilament yarn components may be arranged side by side so as to be parallel to each other along the yarn axis, or they may be arranged in a sheath and core configuration.

In the latter case, the multifilament yarn component with high shrinkage ratio is preferably used in a core part of the latently crimped yarn and the multifilament yarn component with low shrinkage ratio or a normal shrinkage ratio preferably arranged in its shell part.

In the present invention, the latently crimped yarn can be prepared by interlacing the multifilament yarn components together.

The number and size of the fine open and closed loops provided on the surface of the latently crimped yarn of the present invention are small, and the bulkiness of the yarn is relatively small, as shown in Fig. 5.

A property of a yarn according to the invention is that the number of open and closed loops which protrude from the surface of the crimped yarn by more than 0.6 mm, i.e., loops C, is less than 10 warp threads/m, which is thus remarkably small and can be considered negligible.

In other words, in the condition immediately after the yarn is textured into the blended multifilament yarn by means of a swirling current of compressed air in the texturing zone, the latently crimped yarn does not have an external surface structure resembling that of a bulky yarn. However, if this latently crimped yarn is treated with heat in hot water at 98°C for 10 minutes in a tension-free state, the latently crimped yarn per se shrinks due to the shrinkage of the multifilament yarn components with low and high shrinkage ratios, as shown in Fig. 7.

Since the multifilament yarn component having a high shrinkage ratio and the multifilament yarn component having a low shrinkage ratio are interlaced with each other, as already known, the shrinkage of each component filament of a multifilament yarn component having a low shrinkage ratio is smaller than that of each component filament of a multifilament yarn component having a high shrinkage ratio, when this latently crimped yarn per se is shrunk, each component filament of the multifilament yarn component having a low shrinkage ratio Shrinkage ratio emerge from the surface of the yarn to form open and closed loops by shrinkage of the high shrinkage ratio multifilament yarn component, which transforms the latently crimped yarn into a crimped yarn with loops revealed thereon with bulky nature.

The crimped yarn having open and closed loops revealed by the heat treatment has a remarkably increased bulk in which the number of loops B protruding from the yarn surface by more than 0.35 mm is more than 1.5 times greater than that of the blended yarn before the heat treatment, while the number of loops C protruding from the yarn surface by more than 0.6 mm is increased to more than 50 warp ends/m after the blended yarn is subjected to heat treatment at 98ºC for 10 minutes with hot water in a non-shrinking state and then dried.

As described above, the latently crimped yarn of the present invention has latent open and closed loops when manufactured, and the number of loops C protruding from the yarn surface is extremely small. Accordingly, the bulk of this yarn per se is very small, and the surface of the yarn is comparatively smooth, as shown in Fig. 5. Therefore, the running friction of the yarn on an apparatus designed for this process is very small.

Particularly when this yarn is used as a warp yarn of a fabric, the running ability of the yarn in the draw as well as the reed is excellent, whereby the loops of adjacent warps cannot entangle with each other or fray in gaps on the weaving machine. Therefore, this yarn can be used as a warp of a fabric.

In addition, when the fabric is dyed or finished after the weaving process, a fabric with high density and high bulk can be obtained by subjecting it in a tension-free state to a heat treatment (using, for example, dry, wet or steam heat) at high temperatures either alone or in conjunction with a dyeing treatment, which results in the latent open and closed loops of the latently crimped yarn being revealed.

To achieve another object of the present invention of producing the latently crimped yarn, at least two synthetic multifilament yarns having different shrinkage ratios are simultaneously fed into an eddy current zone to create open and closed loops on the surface of the yarn, with the yarn subsequently being drawn to remove or refine the loops.

In the above-mentioned process, the shrinkage ratio of the multifilament yarn with high shrinkage ratio in hot water can be more than 10%, and the difference in the shrinkage ratio in hot water between the multifilament yarn with high shrinkage ratio and the multifilament yarn with low shrinkage ratio can be more than 5%.

Furthermore, a partial filament of the multifilament yarn with a low shrinkage ratio may have a denier of 0.05 - 2.5 d (0.0055 - 0.28 tex), preferably 0.05 - 1.3 d (0.0055 - 0.14 tex), and a partial filament of a multifilament yarn with a high shrinkage ratio may have a denier of 0.1 - 15 d (0.011 - 1.67 tex), preferably 0.3 - 15 d (0.033 - 1.67 tex), and more preferably 1 - 15 d (0.11 - 1.67 tex).

By way of example, a preferred embodiment of the method for producing a latently crimped yarn of the present invention will now be explained with reference to Fig. 1.

Fig. 1 is a schematic representation of an embodiment of the process for producing a latently crimped yarn according to the invention.

As shown in Fig. 1, a multifilament yarn 2 with a high shrinkage ratio, which is unwound from a yarn carrier 1, is fed by feed rollers 3 to a texturing device 4 in which a vortex current zone is created by compressed air is formed. At the same time, a multifilament yarn 6 with a low shrinkage ratio, which is unwound from a yarn carrier 5, is fed to the same texturing device 4 by feed roller 7. These multifilaments 2 and 6 are fed to the texturing device 4 simultaneously by suitable yarn guides 8 and 9.

It should be mentioned that in this process the multifilament yarn 6 can be fed directly to the texturing device 4.

After the multifilament yarns 2 and 6 have been passed through the texturing device 4, in which a vortex flow of compressed air prevails, they are wound onto a yarn carrier 14 as a crimped yarn 10 by means of a first take-up roller 11 and a second take-up roller 12 as well as a winding device 13.

During this process, the thus-produced crimped yarn is stretched between the take-up rollers 11 and 12. This stretching process serves to eliminate large open and closed loops of the crimped yarn and is preferably adjusted so that the development of the open and closed loops is not impaired during the heat treatment. In fact, if the stretching is too weak, the large open and closed loops are not properly eliminated and if the stretching is too strong, the fine open and closed loops of the crimped yarn formed by the eddy current zone are almost completely destroyed.

Preferably, the elimination of loops is carried out in such a way that the fine loops on the surface of the yarn are not visible to the naked eye, but only through a microscope or magnifying glass.

The latently crimped yarn of the present invention is preferably produced under the following conditions.

In the process according to the invention, a multifilament yarn with a shrinkage ratio of more than 10% is hot water having a filament denier of 0.1 - 15 d (0.011 - 1.67 tex), preferably 0.3 - 15 d (0.033 - 1.67 tex), and more preferably 1 - 15 d (0.11 - 1.67 tex) is used as the high shrinkage yarn, and a multifilament yarn having such a shrinkage in hot water that the difference in shrinkage between the multifilament yarn with a high shrinkage ratio and that of the multifilament yarn with a low shrinkage ratio is more than 5%, and a filament denier of 0.05 - 2.5 d (0.0055 - 0.28 tex), preferably 0.05 - 1.3 d (0.0055 - 0.14 tex) is used as the low shrinkage yarn.

From the corresponding feed rollers, these yarns are fed to the 4 texturing device with a different overfeed ratio, in which the eddy current zone with compressed air prevails (in which the supply volume of compressed air is 80 - 120 ml/min), and the crimped yarns, after being removed from the texturing device and having undergone an interlacing and mixing treatment, are wound up by the same take-up rollers.

The lead ratio used in a method according to the invention is based on the following equation:

F(%) = (V₁ - V₂)/V₂ x100

where V₁ is the surface speed of the feed roller and V₂ is the surface speed of the take-up roller.

Note that the lead ratio is only defined if the F value obtained from the equation is positive (+).

In a method according to the invention, the overfeed ratio λ of the high shrinkage multifilament yarn is set to about 2 - 15% and the overfeed ratio β of the low shrinkage multifilament yarn is set to about 5 - 30%. Furthermore, in the present invention, the yarn taken out from the first take-up roll is preferably drawn off by a second take-up roll under continuous stretching at an underfeed ratio of 0.4λ- 0.8 λ up to the overfeed ratio λ of the high shrinkage yarn.

In an embodiment of the present invention, a multifilament yarn having a filament denier of 0.1 - 15 d (0.011 - 1.67 tex) is used as a high shrinkage yarn of the latently crimped yarn. In other words, a desired yarn shrinkage cannot generally be obtained after heat treatment if the filament denier is less than 1 d (0.11 tex) because the shrinkage of the filaments is small and the shrinkage ratio of the yarn is significantly reduced. However, sufficient yarn shrinkage can be obtained even if a filament having a denier of less than 1.0 d (0.11 tex) is used if its content is more than 40% by weight of the yarn. If a filament denier is more than 15 d (1.67 tex), the fabric produced feels coarse and is difficult to handle because the yarn itself is very hard.

It is preferable that the shrinkage of the high shrinkage multifilament yarn is large, although the use of a yarn having a large shrinkage causes further problems in that such a yarn has an inherent instability in size which varies with time, thus the quality of the product made from this yarn cannot be stable. Accordingly, it is preferable to use a multifilament yarn having a shrinkage ratio of 10 to 30%.

On the other hand, a multifilament yarn with a filament denier of 0.05 - 1.3 d (0.0055 - 0.14 tex) is preferably used as a low-shrinkage multifilament yarn.

It should be noted that a multifilament with a filament denier less than 0.5 d (0.005 tex) can be used, but if the denier is very small, the yarn becomes difficult to handle due to the development of fluff. If its filament denier exceeds 1.3 d (0.14 tex), the fine loops are difficult to expose and a fabric made from such a yarn will be rough to handle.

It should also be noted that the shrinkage of the low shrinkage multifilament is preferably as low as possible, but since special yarns generally have problems with regard to yarn texturing ability and dyeing, a multifilament yarn with normal shrinkage (a shrinkage ratio ΔS of about 7.5%) is preferably used.

Namely, the difference in shrinkage ratio between the high shrinkage multifilament yarn and the low shrinkage multifilament yarn must be at least 5%, since the development of the open and closed loops of the latently crimped yarn depends entirely on this difference in shrinkage ratios. In producing the latently crimped yarn of the present invention, the over-feed ratio K of the high shrinkage multifilament yarn is preferably 2 - 15% and the over-feed ratio β of the low shrinkage multifilament yarn is preferably 5 - 30%, and furthermore the difference between the over-feed ratios β - λ is preferably 3 - 15%. These conditions are most suitable for forming fine open and closed loops in the eddy current zone of compressed air.

The latently crimped yarn produced by a method according to the invention is a mixed blended yarn of synthetic multifilament yarns each having different shrinkage ratios and fine open and closed loops on their surface, the number and size of which can be increased by heat treatment in a tension-free or shrinkage-free state.

At the time when the yarn is textured as a multifilament blended yarn by entangling immediately after passing through the eddy current zone, the yarn of the invention must not have an external structure resembling that of a bulky yarn. However, if the latently crimped yarn is kept in a shrinkage-free state by heat treatment with hot water at 98ºC for 10 minutes as described above, treated and dried, many open and closed loops appear on the surface of the yarn and are exposed.

Examples

By means of the yarn manufacturing method shown in Fig. 1, a latently crimped yarn was manufactured under conditions in which the overfeed ratio λ of a high shrinkage multifilament yarn and the overfeed ratio β of a low shrinkage multifilament yarn were set to 9% and 15%, respectively, using a "TASLAN" type spinneret as the texturing device 4 with an air supply volume of 90 Nl/min, and also setting the underfeed ratio between the first and second take-up rollers to 5.4% (i.e. 0.6 λ ).

The high shrinkage and low shrinkage multifilament yarns used were combined as follows:

example 1

High shrinkage yarn: Polyester multifilament 50D (5.55 tex)

- 24F (with a high shrinkage ratio ΔS = 20%)

Low shrinkage yarn: Polyester multifilament 50D (5.55 tex)

- 72F (with a normal shrinkage ΔS = 7.5%)

Example 2

High shrinkage yarn: Polyester multifilament 30D (3.33 tex)

- 12F (with a high shrinkage ratio ΔS = 20%)

Low shrinkage yarn: Polyester multifilament 30D (3.33 tex)

- 48F (with a normal shrinkage ΔS = 7.5%)

Comparison example

High shrinkage yarn: Polyester multifilament 30D (3.33 tex)

- 12F (with a normal shrinkage ΔS = 7.5%)

Low shrinkage yarn: Polyester multifilament 30D (3.33 tex)

- 48F (with a normal shrinkage ΔS = 7.5%).

The yarn shrinkage of the latently crimped yarn thus produced and the properties of the loops before and after the treatment are described in Table 1. Table 1 Example Comparative example Yarn shrinkage (%) before heat treatment after heat treatment before stretch treatment Loop

In Table 1, the yarn referred to as "before heat treatment" is the latently crimped yarn of the invention per se, and the yarn referred to as "after heat treatment" is the crimped yarn prepared from the latently crimped yarn by winding the latently crimped yarn 100 times on a reel of 1 m length to prepare a short strand, then immersing it in hot water at 100°C for 10 minutes in a non-shrinkage state and then drying it.

In addition, the yarn referred to as "before stretching treatment" is a yarn produced by winding the latently crimped yarn taken out from the first take-up reel without stretching.

Fig. 2 is a graph showing the results of the data shown in Table 1.

The properties of the loops of the examples were measured by the following procedure.

The yarn to be measured was passed through a photoelectric fuzz measuring device (e.g., a "TORAY FRAY COUNTER") at a yarn running speed of 50 m/min and a yarn running tension of 0.1 g/d (0.0108 cN/tex) to measure the number of loops on the yarn, and this counted number was displayed as a value per meter based on the measured data obtained in 20 seconds (n = 5).

On the other hand, to measure the yarn after treatment, a test sample was prepared by pulling a short strand onto a reel by hand after drying in air, making sure that no tension was exerted on the yarn. It was then wound onto a bobbin by slowly rotating the reel.

As can be seen from Fig. 2 and Table 1, the number of loops C on the latently crimped yarn in the example of the invention is comparatively small, and although a small number of loops C are seen in the yarn before the stretching treatment, these loops are completely eliminated to produce a condition in which no loops exist on the yarn.

In the processes of Examples 1 and 2, the number of loops of the yarn of classes B and C after treatment is considerably higher in comparison with the number of these loops before treatment. However, conversely, the increase in loops B and C of the comparative example is much smaller.

By comparing the results of Example 2 with those of the Comparative Example, it can be seen that the number of loops B in Example 2 after treatment increases steeply upwards to almost 5 times the number of loops B before treatment, with the number of loops C after treatment also increasing steeply to up to 88 warp threads/m.

In the comparison example, however, the increase in the number of loops B after treatment is only 1.5 times that before treatment, which is considered small, with the number of Loops C after treatment is 11 warp threads/m, so that heating does not lead to an increase in the number of loops C.

Although the variations in the properties of the loops both before and after the stretching treatment were also taken into account, there were no significant differences between them, so only the data relating to the yarn after the stretching treatment are given.

If the number of loops B after heat treatment is not more than 1.5 times greater than the number before treatment, and the number of loops C is not more than 50 warp threads/m, the crimped yarn produced in this way is not preferable, since it has very low bulk and feels coarse.

It is apparent that the properties of the loops of the crimped yarn depend on the shrinkage ratio of the latently crimped yarn and the difference between the shrinkage ratio of the high and low shrinkage yarns. Namely, in the comparative example, there is no difference in the shrinkage ratio of the two yarns, and accordingly the variation in the properties of the loops before and after the treatment is very small, and there are little differences between the loops on the yarn formed in the eddy current zone and those on the yarn after the heat treatment.

In comparison, the properties of the loops on the already heat-treated yarn prepared in the examples can be significantly improved because the shrinkage difference between the high- and low-shrinkage yarn is large and, moreover, the high-shrinkage yarn has a large shrinkage ratio, these factors exerting a synergetic effect on the yarn.

Example 3

In the process illustrated by Fig. 1, a polyester multifilament yarn, 75D (8.33 tex) - 36F, with a shrinkage ratio in hot water of 15%, consisting of 18 warp ends of filaments with a shrinkage ratio in hot water of 20% as high shrinkage component and 18 warp ends of filaments with a shrinkage ratio in hot water of 8% as low shrinkage components, were used as core yarn, a polyester multifilament yarn, 75D (8.33 tex) 96F, with a shrinkage ratio of 8% in hot water was used as sheath yarn, and these yarns were fed to a texturing zone provided with a "TASLAN" spinneret at a core yarn overfeed ratio of +9% and a sheath yarn overfeed ratio of +20% and textured under high pressure of 8.0 kg/cm².

The yarn treated in this way was then wound onto a yarn carrier under stretching between the first and second take-up rollers at an underfeed ratio of -6.5%.

The yarn characteristics obtained are as follows:

Yarn shrinkage ratio 14.2%

Number of loops at the beginning of the texturing process

Loop A 428 warp threads/m

Loop B 360 warp threads/m

Loop C 15 warp threads/m

Number of loops after elimination

Loop A 317 warp threads/m

Loop B 78 warp threads/m

Loop C 3 warp threads/m

Number of loops after processing

Loop A 395 warp threads/m

Loop B 320 warp threads/m

Loop C 45 warp threads/m

The data of the number of loops after processing are converted data in which the raw data are modified by the shrinkage feature. Also, in the data of the number of loops after processing, the number of loops C higher than that of the same loops measured at the beginning of the texturing process. This is because a loose or sagging filament area created by yarn shrinkage is counted in addition to the loops being worked up.

Example 4

In the process illustrated by Fig. 1, a polyester multifilament yarn, 75D (8.33 tex) - 36F, with a shrinkage ratio of 20% in hot water is used as a core yarn and a polyester multifilament yarn, 75D (8.33 tex) - 96F, with a shrinkage ratio of 10% in hot water is used as a sheath yarn, these yarns were fed to a texturing zone equipped with a "TASLAN" spinneret at a core yarn overfeed ratio of +12% and a sheath yarn overfeed ratio of +20% and textured under high pressure at 6.0 kg/cm2.

The yarn treated in this way was then wound onto a yarn carrier under stretching between the first take-up roller and the second take-up roller at an underfeed ratio of -3.0%.

The yarn characteristics obtained are as follows:

Yarn shrinkage ratio 10.4%

Number of loops at the beginning of the texturing process

Loop A 620 warp threads/m

Loop B 430 warp threads/m

Loop C 165 warp threads/m

Number of loops after elimination

Loop A 546 warp threads/m

Loop B 175 warp threads/m

Loop C 4 warp threads/m

Number of loops after processing

Loop A 573 warp threads/m

Loop B 397 warp threads/m

Loop C 182 warp threads/m

Bulkness of the yarn (cm³/g)

at the beginning of the texturing process 17.5

after elimination 4.51

after processing 19,19

Increase in bulk (%) 432

The bulk measurement was performed using a method defined in the Japanese Industrial Standard (JIS) L 1059C.

The latently crimped yarn produced according to this invention can be unwound from a yarn carrier much better and has excellent yarn unwinding properties at high yarn speeds.

For example, an extremely wide range of thermoplastic synthetic filaments can be used in this invention without regard to any limitations on the filament denier or the cross-sectional shape of a component of the sheath yarn.

Furthermore, when using the latently crimped yarn according to the invention as the warp yarn of the fabric, the runnability of the yarn in the draw and the reed is excellent, with no possibility of the loops of adjacent warps entangling with each other or fraying in gaps.

Therefore, a fabric with a high yarn density can be produced if this crimped yarn is used as a warp yarn.

Furthermore, in this invention, the fabric can be subjected to a relaxed heat treatment after the weaving process without tension, whereby the entire latently crimped yarn can move during the reworking to regain the loop shape formed at the beginning of the texturing process.

Therefore, depending on the method and conditions of the relaxed heat treatment, a remarkable fabric that feels different and has different surface textures.

Furthermore, the latently crimped yarn of the present invention is a mixed multifilament blend yarn on whose surface open and closed loops are prominent, and although the number of large loops classified into group C is very small, it has excellent properties in that the number of large loops classified into loops B and C is remarkably increased and therefore the weaving process can be carried out with high efficiency when it is heat-treated.

In this invention, moreover, the fabric produced can be handled in a convenient manner because the shrinking process by means of the heat treatment carried out after the weaving process can produce a fabric with a high density, exposing a large number of open and closed loops on the surface of the fabric.

In the case of a conventionally crimped yarn, it was necessary to provide its surface with as many open and closed loops as possible in order to produce a fabric after dyeing and finishing that was pleasant to the touch and easy to handle. However, if a yarn having many open and closed loops is used as the warp yarn, there are many problems in the weaving process, as mentioned above.

Consequently, in the conventional practice of using such a crimped yarn as a warp yarn, either the yarn density or the number of open and closed loops must be reduced in order to maintain the efficiency of weaving at a mass production level. However, this reduction in the number of open and closed loops results in the fabric not feeling so comfortable or in its surface finish deteriorating.

In a conventionally crimped yarn, the efficiency of weaving the crimped yarn with a minimum loop content to produce a fabric with a pleasant spun-like feel is such that the loom downtime count indicated per 24 hours per loom was 24.1 counts/24 hr loom as shown in Table 2, which is a poor result in comparison with the standard value of 10 counts/24 hr loom required for mass production.

The fabric panels produced under these poor processing conditions were worthless as end products and were therefore not commercially available.

In contrast, the latently crimped yarn of the present invention can exert a remarkable effect on the weaving ability in that the loom downtime count is low at 4.3 counts/24 loom hours, as shown in Table 2.

In this invention, the number of open and closed loops can be adjusted to any desired level by merely changing the difference in the shrinkage ratio of the core and sheath yarns, the shrinkage ratio of the core yarn, and the overfeed ratio of both the core and sheath yarns.

Consequently, many excellent functions and effects such as expanding the possibility of fabric design can be obtained in this invention. Table 2 Warp yarn 70D (7.77tex) - 48F 70D (7.77tex)-60F Conventional crimped yarn Latent crimped yarn Loop characteristic Weaving ability Weaving conditions Loop A (warp threads/m) Loom downtime count Weaving construction Weaving density (warp x weft) Loom revolutions Weft yarn Smooth Latent crimped yarn * Loom downtime count caused by warp yarns

Next, spun-like fabrics having a high yarn density produced by using the latently crimped yarn of the present invention mainly as warp yarns are described as follows.

As described above, the manufacturing process of a fabric having a spinning-like handling using a crimped yarn consisting of multifilament yarns having many open and closed loops on their surface and manufactured by, for example, the "TASLAN" process is already known.

However, this conventional yarn can only be used as the weft yarn of the fabric, and there is a strict restriction on the use of such a yarn as the warp yarn of the fabric because the yarn is difficult to handle and difficult to pass through in a weaving process.

In this invention, by using the latently crimped yarn, all the above-mentioned disadvantages can be overcome, whereby a high-density fabric having a soft and spun-fiber-like feel can be produced by using a mixed multifilament blend yarn having open and closed loops as a warp yarn.

According to the invention, the spun-like fabric using a latently crimped yarn has a high-density fabric construction in which a mixed multifilament blended yarn consisting of synthetic multifilament yarn components having open and closed loops on its surface is used at least as a warp yarn of the fabric, the coverage factor of the warp yarns of the fabric being more than 1100.

In this fabric, the latently crimped yarn used as a warp yarn is preferably a blended multifilament yarn comprising at least two multifilament yarn components, each having a different shrinkage factor.

The fabric of the present invention will now be explained in more detail.

By using a latently crimped yarn consisting of synthetic multifilament yarn components with open and closed loops as the warp yarn, the open and closed loops are arranged in a disordered manner on the surface of the fabric, whereby this fabric is pleasant to handle due to these loops present on its surface, similar to a yarn spun from fluff flakes, while at the same time it feels uneven like a fabric made from spun yarn, because the arrangement of the warp and weft yarns existing multifilament yarns is not regular from an optical point of view.

It should be noted that the smaller the denier of a partial filament, the better the spun-fiber-like fabric feels.

Furthermore, in a fabric according to the invention, it must be reduced to a high density fabric so as to have a soft and spun-fiber-like feel and be comfortable to handle by open and closed loops present in a mixed state on the surface of the fabric made from the crimped yarn, thus imparting a suitable rigidity to the fabric and avoiding the problems of clogging or dust accumulation caused by the loops.

Therefore, in the fabric of the invention, the yarn density of the warp yarn must be adjusted so that the coverage factor of the mixed multifilament blend yarn with open and closed loops used as the warp yarn of the fabric which has already been dyed and finished is more than 1100, preferably less than 1600.

Generally speaking, when the coverage factor of the warp yarn is more than 1100 as mentioned above and a weaving is carried out using such a mixed multifilament blended yarn with open and closed loops, these loops provided on each adjacent strand are interwoven with each other by repeated mutual contact caused by fraying on the loom, so that problems such as gappy fraying or nap formation occur and therefore a fabric of good quality cannot be produced on a mass production scale.

In contrast to the conventionally crimped yarn, this invention uses the latently crimped yarn to improve the throughput of the yarn in the weaving process, so that a fabric with a relatively high yarn density compared to can be woven into a fabric made from conventionally crimped yarn, and furthermore this fabric can be converted into a fabric with a high yarn density by shrinking by means of heat treatment in the shrink-free state, e.g. a relaxed treatment during dyeing and finishing.

This invention can produce a high-density fabric even if a mixed multifilament yarn having open and closed loops is used as a warp yarn.

Compared with a fabric made from conventionally crimped yarn by an eddy current, the fabric of the invention has finer surface features because the loops potentiated in the yarn are exposed in the fabric by a loop development treatment and thus the number of loops exposed at the crossing point of the warp and weft yarns is very small.

As already known, in a normal fabric of normal weave construction, the surface finish or handling of a fabric depends mainly on the effect of a warp yarn, although, if the latently crimped yarn is the same yarn used as the warp yarn is used for the weft yarn, a fabric with high yarn density can be produced using the crimped yarn as both the warp and weft yarn, and its handling and the spun fiber-like and soft feeling of its surface are far better than those of a fabric made from the crimped yarn produced by an eddy current and used as the weft yarn.

Furthermore, as the weft yarn which can be used in a fabric according to the invention, the mixed multifilament blend yarn comprising at least two synthetic multifilament yarn components each having a different shrinkage ratio and a total shrinkage ratio in hot water of more than 10%, or a yarn having a low shrinkage ratio in hot water but a shrinkage ratio of more than 10% in dry heat, or even a spun blend yarn consisting of staple fibers each having a different shrinkage ratio.

As the low shrinkage component of the blended multifilament yarn or spun yarn, it is preferable to use fibers or filaments having a smaller single fiber denier than that of the fiber used in the high shrinkage component in order to produce a fabric that has a pleasant feel and an outer structure similar to spun fibers and in which settling effects and dust accumulation are avoided.

It should be noted that the latently crimped yarn of the structure described above can be used for a fabric with a high yarn density.

The most preferred yarn construction of the latently crimped yarn of this invention is such that the high shrinkage ratio multifilament yarn component is preferably arranged as the core part of the latently crimped yarn and the low or normal shrinkage ratio multifilament yarn component is preferably arranged as the sheath part thereof, although the yarn construction of this invention is not limited to this construction.

The manufacturing process for producing the latently crimped yarn set forth above can also be used in processes for producing a high density fabric as described above.

As described above, the latently crimped yarn of the present invention has latently opened and closed loops during production, and the number of loops C protruding from the surface of the yarn is extremely small. Accordingly, the bulk of the yarn per se is very low and the surface of the yarn is comparatively smooth, thereby reducing its yarn running friction. in a device used in this process is very low.

Particularly when this yarn is used as a warp yarn on a fabric, the yarn's running ability in the head and the reed is excellent, and the loops of adjacent warps cannot intertwine with one another or fray in gaps on the weaving machine. Therefore, this yarn can be used as a warp on a fabric.

Furthermore, when the fabric is dyed or finished after the weaving process, a fabric with high density and high bulk can be produced by subjecting it in the tension-free state to a heat treatment (using, for example, dry, wet or steam heat) at high temperatures either alone or together with a dyeing treatment, which results in revealing the latent open and closed loops of the latently crimped yarn.

Example 5

In the process illustrated by Fig. 1, a shiny polyester multifilament yarn, 50D (5.55 tex) - 24F, with a round cross-section and a shrinkage ratio of 20% in hot water, was used as a part yarn, preferably as a core yarn, a shiny polyester multifilament yarn, 50D - 72F, with a round cross-section and a shrinkage ratio of 7.5% in hot water was used as a part yarn, preferably as a sheath yarn, and these yarns were fed to the texturing zone with an eddy current spinneret at a core yarn overfeed ratio of +9% and a sheath yarn overfeed ratio of +15% and textured at an air supply volume of 90 Nl/min.

The yarn treated in this way was then wound onto a yarn carrier under stretching between the first and second take-up rollers at an underfeed ratio of -5.4%.

The yarn properties obtained are as follows:

Total yarn denier 06 D (11.78 tex)

Yarn shrinkage ratio 17.8%

Number of loops before heat treatment

Loop A 447 warp threads/m

Loop B 125 warp threads/m

Loop C 1 warp thread/m

Number of loops after heat treatment

Loop A 438 warp threads/m

Loop B 390 warp threads/m

Loop C 168 warp threads/m

Then, the latently crimped yarn thus produced was used as warp and weft yarns to produce a smooth fabric using a water jet loom with a warp yarn density of 85 warp ends/inch (33.5 warp ends/cm) (the warp yarn coverage factor was 850) and a weft yarn density of 78 warp ends/inch (30.7 warp ends/cm).

The natural colored fabric was then subjected to the following treatments; a relaxed treatment, an intermediate fixation, an alkali weight loss treatment (5%), dyeing and finishing to obtain a high density fabric with a warp yarn density of 117 warp threads/inch (46.1 warp threads/cm) (the warp yarn coverage factor was 1170) and a weft yarn density of 100 warp threads/inch (39.4 warp threads/cm).

Expressed as yarn density (warp ends/inch), n, and yarn denier, d, the cover factor (CF) is given by the equation

CF = n

given.

Expressed as yarn density (warp threads/cm), nSI and yarn-tex the cover factor (CF) is given by the equation

CF = (2.54/9)nSI = 7.62NSI

given.

The resulting fabric has open and closed loops in a mixed state on its surface and feels very soft and spun-fiber-like, similar to a fabric made from spun fiber yarn, because the surface of the fabric according to the invention is covered with fine and micronized loops, and the yarn is also very stiff due to the high yarn density.

Example 6

In the process illustrated by Fig. 1, a shiny polyester multifilament yarn, 30D (3.33 tex) - 12F, with a round cross-section and a shrinkage ratio of 20% in hot water was used as a part yarn, preferably as a core yarn, a shiny polyester multifilament yarn, 30D (3.33 tex) - 48F, with a round cross-section and a shrinkage ratio of 7.5% in hot water was used as a part yarn, preferably as a sheath yarn, and these yarns were introduced into the texturing zone, which was provided with an eddy current spinneret, at a core yarn overfeed ratio of +9% and a sheath yarn overfeed ratio of +15% and textured at an air supply volume of 90 Nl/min.

The yarn treated in this way was then wound onto a yarn carrier under stretching between the first and second take-up rollers at an underfeed ratio of -5.4%.

The yarn properties obtained are as follows:

Total yarn denier 63 D (7.0 tex)

Yarn shrinkage ratio 18.4%

Number of loops before heat treatment

Loop A 332 warp threads/m

Loop B 72 warp threads/m

Loop C 1 warp thread/m

Number of loops after heat treatment

Loop A 416 warp threads/m

Loop B 330 warp threads/m

Loop C 88 warp threads/m

The latently crimped yarn thus produced was then used as warp and weft yarn to produce a smooth fabric using a water jet loom with a warp yarn density of 142 warp threads/inch (55.9 warp threads/cm) (the warp yarn coverage factor was 1100) and a weft yarn density of 110 warp threads/inch.

The natural colored fabric was then subjected to the following treatments; a relaxed treatment, an intermediate fixation, an alkali weight loss treatment (5%), dyeing and finishing to obtain a high density fabric with a warp yarn density of 177 warp threads/inch (69.7 warp threads/cm) (the warp yarn coverage factor was 1370) and a weft yarn density of 135 warp threads/inch (53 warp threads/cm).

The fabric thus obtained has open and closed loops in a mixed state on the surface of the fabric and has a very soft and spun-fiber-like feel, similar to a fabric made from spun yarn, because the surface of the fabric according to the invention is covered with fine and micronized loops, and the yarn is also very stiff due to the high yarn density.

The fabric according to the invention has a high density, although it is stiff due to the bulkiness of the yarn and at the same time has improved waterproof properties, and when it has been subjected to a water-repellent finish after dyeing, it is suitable for use in sporting goods, in particular for ski clothing.

If the high-density spun-like fabric of the present invention is further developed, another high-density spun-like fabric suitable for coats or outerwear for sportswear which particularly requires waterproof or windbreaking properties can be produced.

By producing a fabric according to the invention as explained below, the technical problems described above can be eliminated with particular reference to JP-A-57-117647, whereby a spun fiber-like fabric can be provided that is not only waterproof and moisture-permeable, but also feels like spun fiber and looks like outdoor clothing.

The above-mentioned fabric has a construction in which the above-described latently crimped yarn is used as a warp yarn and a synthetic multifilament yarn in which all the component filaments have a flat cross-sectional shape is used as a weft yarn, the total coverage factor of the warp and weft yarns being 1800 to 3500.

In a high-density fabric according to the present invention, a latently crimped yarn is used as the crimped yarn for the warp yarn, and the latently crimped yarn is preferably a blended yarn having a sheath-core yarn configuration in which the single component filament of the synthetic multifilament yarn used as the core part of the blended yarn has a relatively large denier and the single component filament of the synthetic multifilament yarn used as the sheath part of the blended yarn has a relatively small denier. Note that the yarn construction in the fabric according to the present invention is not limited to a sheath-core blended yarn.

In general, the high-density fabric is very stiff and difficult to handle because the movement of the yarns among each other is relatively restricted within the high-density fabric.

Accordingly, as a yarn component of the sheath part of the blended yarn, an ultrafine multifilament yarn having a partial filament denier of 0.05 - 1.3d (0.0055 - 0.14 tex) is used, and furthermore, a multifilament yarn having a partial filament denier of 0.1 - 15d (0.011 - 1.67 tex) is preferably used as a yarn component of its core part, so that the fabric can be given bulky and elasticity.

Both the above-mentioned yarn construction and the yarn manufacturing method can be applied to the yarn construction of the latently crimped yarn and its manufacturing method in this embodiment. On the other hand, a Flat ratio of the filaments having a flat cross-sectional shape consisting of synthetic multifilament and used as weft yarn in this embodiment, preferably 2.0 - 6.0.

If the flat ratio is less than 2.0, the waterproofness and windbreakability mainly provided by the flatness of the filament will be small, but on the other hand, the gloss of the fabric will be increased, while its spun-fiber-like feel or external texture caused by the warp yarn will be reduced if the flat ratio is more than 6.0. Consequently, the preferred flat ratio ranges from 2.0 to 6.0.

The flat ratio of this embodiment is represented by "b/a" where "a" and "b" are the thickness and lateral dimensions of the cross-sectional shape, respectively, as shown in Fig. 3.

Since the multifilament having a flat cross-sectional shape is naturally arranged in a precise direction in the fabric, the space between adjacent yarns can be reduced and made extremely small, thus increasing the waterproofness and moisture permeability of the fabric. In a fabric woven entirely from multifilament yarns having a flat cross-sectional shape, problems arise in that the fabric feels smooth and has a strong gloss caused by light reflected from the surface of the fabric. However, these problems can be eliminated by using a fabric according to the invention due to the resistance of the open and closed loops on the surface of the fabric, which leads to a reduction in smoothness and gloss.

When a multifilament with a flat cross-sectional shape is used in weaving processes, the filaments are preferably not heat treated, such as with a false twisting process, whereby post-twisting is avoided as far as possible in order to initiate the shrinkage of the filaments. Even when using If this yarn is used as a warp yarn, the retwisting rate should be less than about 300 passes/m.

For producing a blended yarn having a high shrinkage and a low shrinkage multifilament yarn component to provide a latently crimped yarn according to the present invention, there can be used a direct spinning and drawing process, a filament blending process in which high shrinkage multifilament yarns and low shrinkage multifilament yarns are first spun and then blended, or a filament blending process in which two high shrinkage multifilament yarns are spun and then one of the yarns is heat treated using a hot plate to produce a low shrinkage multifilament which is then blended with the non-heat treated high shrinkage multifilament yarn. An example of a high density fabric mentioned above will now be explained.

Example 7

In the process illustrated by Fig. 1, a shiny polyester multifilament yarn, 30D (3.33 tex) - 12F, with a round cross-section and a shrinkage ratio of 20% in hot water was used as a part yarn, preferably as a core yarn, and a shiny polyester multifilament yarn, 30D (3.33 tex) - 48F, with a round cross-section and a shrinkage ratio of 8% in hot water was used as a part yarn, preferably as a sheath yarn, and these yarns were introduced into the texturing zone, which was provided with an eddy current spinneret, at an overfeed ratio of the core yarn of +9% and an overfeed ratio of the sheath yarn of +15% and textured at an air supply volume of 90 Nl/min.

The yarn treated in this way was then wound onto a yarn carrier under stretching between the first and second take-up rollers at an underfeed ratio of -5.4%.

The crimped yarn thus produced had a total yarn denier of 63D (6.7 tex) and a shrinkage ratio of 18.4% in hot water, with the number of loops before Heat treatment was such that loops A amounted to 332 warp threads/m, loops B amounted to 72 warp threads/m and loops C amounted to 1 warp thread/m, while their number after treatment, ie shrinkage in hot water in the shrinkage-free state, was such that loops A amounted to 416 warp threads/m, loops B amounted to 330 warp threads/m and loops C amounted to 88 warp threads/m, these latently crimped yarns being used as warp yarns.

Furthermore, as a weft yarn, a shiny polyester multifilament, 50D (5.55 tex) - 24F, each component filament of which had a flat cross-sectional shape and a flat ratio of 4.5 and which had a total shrinkage of 15.7% in hot water, consisting of a multifilament yarn, 25D (2.77 tex) - 12F, having a shrinkage ratio of 16.5% in hot water and a multifilament yarn, 25D (2.77 tex) - 12F, having a shrinkage ratio of 10.3% in hot water, was spun by direct spinning and drawing processes. Subsequently, a fabric panel was woven with a warp yarn density of 114 warp ends/inch (44 warp ends/cm) and a weft yarn density of 120 warp ends/inch (47 warp ends/cm) and a total cover factor, i.e. a sum of the cover factors of warp and weft, of 1730. In this embodiment, the method for measuring the cover factor as described above is also used.

The fabric thus produced was then dyed using a conventional relaxation and dyeing process and then finished with a water-repellent agent.

The final fabric treated in this way had a warp yarn density of 156 warp threads/inch (61 warp threads/cm) and a weft yarn density of 146 warp threads/inch (57 warp threads/cm) and a total coverage factor, i.e. the sum of the coverage factors of warp and weft yarns, of 2240.

In addition, the fabric has various functionally valuable features, namely a waterproof pressure of 560 mm, a mesh strength of 90 points and a moisture permeability of 8200 g/cm²/24 h, making it a high-quality A high density fabric that feels like spun fiber and has an external structure that cannot be achieved with a fabric made from conventionally textured yarn, such as "TASLAN".

In the above-mentioned example, the latently crimped yarn according to the invention is mainly used as a warp yarn.

However, the latently crimped yarn according to the invention does not have to be used only as a warp yarn, but can be used both as a weft and as a warp yarn or only as a warp yarn.

Next, a spun-fiber-like, high-density fabric having a softer feel than that produced in the example immediately above was produced by a process for producing a fabric according to the invention.

This fabric had the following fabric construction. A high density blended fabric in which mixed multifilament blended yarns consisting of at least one synthetic multifilament yarn component that can shrink and whose surface is provided with fine open and closed loops were used as warp yarns, with spun yarns being used as weft yarns or as warp yarns, and this fabric was further characterized in that the total coverage factor of the warp yarns and weft yarns was 2000 to 3500.

In this embodiment, a fabric with a high yarn density that could not previously be produced from spun yarns could be produced, and in addition a fabric with a previously unknown good handling and a spun fiber-like outer structure was produced, which are caused by the fluff of the spun yarns and the open and closed loops of the multifilament yarn components that are connected to one another.

In this embodiment, the latently crimped yarns can be used as warp or weft yarns or both.

The yarn construction and the method of manufacturing it, as mentioned above, can be used in this embodiment. However, since the latently crimped yarn is used in this embodiment, the preferred yarn construction is the same as the construction of the latently crimped yarn used as the warp yarn explained in the previous embodiment.

In this embodiment, when the latently crimped yarn is used as a warp yarn and the spun yarn is used as a weft yarn, a fabric having an extremely high yarn density which cannot be realized by using the conventionally crimped yarn can be produced because the latently crimped yarn has a straight configuration which cannot be recognized as a crimped yarn at a glance and is completely different from a crimped yarn produced by a conventional eddy current.

Accordingly, in this embodiment, a fabric can be woven with a warp yarn density as high as possible and with spun yarns as the warp yarn having a normal or higher density, and then the thus woven fabric sheet is shrunk in the warp direction by shrinkage carried out in a later process such as dyeing to convert the fabric sheet into a fabric with a high weft yarn density and at the same time produce a fabric having a high density and having a high-quality spun-like effect both in terms of how it feels and in terms of the external structure without losing the effect of handling.

The latently crimped yarn can also be used with re-twisting.

A spun yarn can be a yarn made from natural fibres such as cotton, wool, linen or silk or from synthetic fibres such as polyester, nylon or acrylic. or a spun blend yarn of at least two kinds of fibers selected from those mentioned above.

When considering the count of the spun yarn, a count such as more than 30S (less than 19.68 tex) in an English cotton numbering system is desired to produce a thin fabric. In addition, in this embodiment, the spun yarn is preferably used as a single yarn.

In the case of high density fabric in which the spun yarns are used as warp yarns, by using as warp yarn the latently crimped fabric having a shrinkage ratio of more than 10% in hot water, preferably more than 15%, which has open and closed loops, the fabric can be woven with a comparatively coarser yarn density than the desired yarn density by taking into account the increase in density caused by the shrinkage of the weft yarn. When the fabric is subsequently dyed to bulk it up, the bulk and its high density can convert it into a fabric with a much higher yarn density while increasing the nap density of the weft yarn.

Example 8

In the processes explained below, a single spun yarn made of 100% polyester with a cotton count of 60 S (9.84 tex) is used as the warp yarn and a latently crimped yarn is used as the warp yarn.

In the process shown in Fig. 1, a shiny polyester multifilament yarn, 30D (3.33 tex) - 12F, with a round cross-section and a shrinkage ratio of 20% in hot water was used as a part yarn, preferably as a core yarn, a shiny polyester multifilament yarn, 30D (3.33 tex) - 48F, with a round cross-section and a shrinkage ratio of 7.5% in hot water was used as a part yarn, preferably as a sheath yarn, and these yarns were spun at an overfeed ratio of the core yarn of +9% and an overfeed ratio of the sheath yarn of +15% were introduced into the texturing zone, which was equipped with an eddy current spinneret, and textured at an air supply volume of 90 Nl/min.

The yarn treated in this way was then wound onto a yarn carrier under stretching between the first and second take-up rollers at an underfeed ratio of -5.4%.

The crimped yarn thus prepared had a total yarn denier of 63D (7.0 tex) and a shrinkage ratio in hot water of 18.4%, the number of loops before the heat treatment being such that loops A were 332 warp ends/m, loops B were 72 warp ends/m and loops C were 1 warp end/m, while their number after the treatment, i.e. shrinkage in hot water in the shrinkage-free state was such that loops A were 416 warp ends/m, loops B were 330 warp ends/m and loops C were 88 warp ends/m.

Then, a plain fabric was woven with the above-mentioned warp and weft yarns using a rapier loom, and then the thus-obtained natural-colored fabric was treated by an ordinary relaxation and dyeing process using a jet dyeing machine. The thus-obtained fabric was impregnated with water-repellent properties and, after fixation, its back surface was calendered for finishing, whereby the thus-finished final product had improved functions attributable to an increase in warp yarn density and a desirable finishing effect with excellent texture and external structure, which cannot be obtained by conventional methods as indicated below.

In addition, the weaving ability of the fabric was excellent and problem-free.

In a comparative embodiment described below, the fabric was spun with 100% single cotton spun yarns with a cotton count of 80 S (combed cotton yarn) (7.38 tex). Example Comparison example Warp yarn density x weft yarn density of the natural colored fabric (warp threads/inch) [warp threads/cm] (coverage factor) Warp yarn density x weft yarn density of the fabric after dyeing Waterproof Pressure (mm) Moisture permeability (g/cm²/24 h)

Example 9

In this example, a plain fabric panel was woven with a latently crimped yarn used as the weft yarn in Example 8 as the warp yarn and with 100% plain cotton spun yarn having a cotton count of 80S (combed cotton yarn) (7.38 tex) as the weft yarn in a circular loom.

The fabric thus produced was then treated successively with a dyeing process that involved relaxation, intermediate fixation, dyeing and finishing, water-repellent treatment and calendering on the back of the fabric.

The resulting fabric had a similar feel and external structure to a fabric made from 100% spun yarns, while providing excellent functions as explained below. Warp yarn density x weft yarn density of the natural colored fabric (warp threads/inch) [warp threads/cm] (coverage factor) Warp yarn density x weft yarn density of the fabric after dyeing Waterproof pressure (mm) Moisture permeability (g/cm²/24 h)Warp yarn density x weft yarn density

The coverage factor used in this embodiment is obtained by the following equation:

Coverage factor = [warp yarn density (warp threads/inch) + weft yarn density (warp threads/inch)]

x

where d represents the multifilament yarn denier, and when using a spun yarn, the cotton count S is converted to denier d by the equation: 5315/cotton count.

As a spun-like fabric, a fabric made of high quality cotton, in particular a spun yarn having a cotton count of more than 60 S (less than 9.84 tex) is required, the yarn consisting of cotton fibers having a very high staple length, so that many attempts have been made to produce a fabric with a handling similar to that of a fabric using synthetic fibers.

Their handling and texture have reached a high level, which is due to improvements in spinning and yarn texturing technology, in particular the refinement of filament denier to an ultra-fine denier or the production of an alternately twisted false twist yarn or a false twist blended yarn of the core-sheath type or the like.

Nevertheless, from an optical point of view, it was not possible to achieve the fluffy texture caused by cotton fibers in this way.

For this purpose, a fabric made of a crimped yarn produced by an eddy current treatment was proposed and developed, although it is difficult to impart to this fabric, even if the cotton fibers feel fluffy due to the surface effect of the loops, a special bulkiness due to the cotton with super-high fiber length, a smooth surface finish, and a stiffness caused by high yarn density.

However, when the latently crimped yarn of this invention is used in a fabric, a fabric having a feel like cotton with super-long fibers and also having a smooth surface texture, fluffiness and stiffness caused by the yarn density can be produced.

Such a fabric can be made as described below. A fabric having a spun-like feel and resembling a fabric made from super long cotton fibers is produced by a process in which the fabric is woven from multifilament blended yarns having a total denier of less than 90d (9.99 tex), wherein the blended yarn consists of multifilament yarn components of filament "a" having a shrinkage ratio of more than 12%, a partial filament denier of more than 1.5d (0.17 tex), and a total denier of the multifilament yarn component of less than 60d (6.67 tex), and multifilament yarn components of filaments "b" having a shrinkage ratio of less than 10% in hot water, a partial filament denier of less than 1.0d (0.11 tex), and a total denier of the multifilament yarn component of less than 60d (6.67 tex), the blended yarn being further characterized by there are more than 300 warp threads/m of Class A loops, more than 50 warp threads/m of loops of class B and less than 10 warp threads/m of loops of class C, each class A, B, C being as defined below, and the fabric is subsequently shrunk to induce a differential shrinkage between filaments "a" and filaments "b" resulting in the open and closed loops of filaments "b" standing out on the surface of the fabric, the measurement and counting of the loops for their assignment to the relevant classes A, B and C being carried out by the method described above.

As the blended yarn used in this embodiment, a latently crimped yarn having the construction already explained can be used, and its manufacturing method is in any case the same as that described above.

The multifilament yarn material used in this embodiment may be any synthetic material, but is most preferably a polyester.

A high shrinkage ratio multifilament yarn component and a low shrinkage ratio multifilament yarn component may be arranged in a sheath-core configuration in the latently crimped yarn or adjacent therein.

Furthermore, in this embodiment, the latently crimped yarn can be used as a warp yarn or as both a warp and weft yarn.

If the latently crimped yarn is used only as a warp yarn, the coverage factor of the warp yarn in a natural-colored fabric is preferably more than 800, and more preferably more than 1100.

If the latently crimped yarn is used as both warp and weft yarn, the total coverage factor, i.e. the sum of the coverage factors of the warp and weft yarns, in a natural-colored fabric is 1500 - 2700, preferably 1800 - 2500.

It is desirable that the warp yarn of this embodiment be twisted more than 300 T/m to provide a handling and an external structure that is almost spun fiber-like in feel, which is provided by the super long fibers.

The embodiment described above will now be explained in more detail.

In order to make the super long fibers feel fluffy, it is suitable to use the latently crimped yarn of the present invention, and in order to obtain a smooth surface finish similar to that of super long fibers, it is effective to use a multifilament blended yarn having a total denier of less than 90D (9.99 tex), more preferably less than 70D (7.77 tex), which comprises component filaments having a denier of less than 1.0d (0.11 tex), more preferably less than 0.7d (0.077 tex) as a sheath yarn.

The super long fibers as used in this embodiment are, for example, Egyptian cotton or Sea Island cotton having a comparatively high fiber length, whereby a spun yarn made from such cotton fibers can have a cotton count of more than 605 (less than 9.84 tex), preferably more than 805 (more than 7.38 tex) and a thickness of 10 µ - 14 µ.

According to the inventors' investigations on a polyester blend yarn having open and closed loops on its surface created by eddy current treatment, the yarn was stiff and the effect of the fabric made from this yarn was unsatisfactory when the single filament denier was more than 10 µ, i.e. its thickness was more than 1d (0.11 tex).

On the other hand, when a single filament denier is less than 1d, a fabric with a smooth surface finish can be produced, and particularly when its denier less than 0.7d (0.077 tex) (less than 8.5 µ), an excellent effect can be produced.

This is attributed to the fact that when a cotton fiber is used, only the fluff gradually emerges on the surface of the spun yarn, whereas in the polyester blend yarn, on the other hand, the fluff consists of loops and thus its stiffness is twice that of each filament.

In order to produce a fabric made of spun yarn consisting of fibers that are super long and stiff and have high density, the fabric must be woven at least with a high warp yarn density, although it is difficult to weave a fabric from a conventional blended yarn produced by conventional eddy current treatment because the loops of the warp yarn hinder fraying.

Therefore, in this embodiment, a method is adopted in which, during weaving, the loops of the warp yarn are kept small, i.e., in a latent state, and in the dyeing and finishing after the weaving process, the yarn is shrunk to develop the loops on the surface of the fabric and at the same time convert the fabric into one with a high density.

Next, an example of the above-described embodiment will be explained.

Example 10

In the process illustrated by Fig. 1, a polyester multifilament yarn, 20D (2.22 tex) - 8F, with a shrinkage ratio of 20% in hot water is used as the core yarn and a polyester multifilament yarn, 20D (2.22 tex) - 48F, with a shrinkage ratio of 8% in hot water, these yarns were fed to a texturing zone provided with an eddy current spinneret at a core yarn overfeed ratio of +9% and a sheath yarn overfeed ratio of +15% and textured at an air supply volume of 90 Nl/min.

The yarn treated in this way was then wound onto the yarn carrier under stretching between the first and second take-up rollers at an underfeed ratio of -5.4%.

The yarn characteristics thus obtained are shown below.

Total yarn denier 43 D (4.77 tex)

Yarn shrinkage ratio 19.2%

Number of loops before heat treatment

Loop A 330 warp threads/m

Loop B 71 warp threads/m

Loop C 1 warp thread/m

Number of loops after heat treatment

Loop A 441 warp threads/m

Loop B 328 warp threads/m

Loop C 86 warp threads/m

The latently crimped yarn thus produced was then used as warp and weft yarn to produce a smooth fabric with a warp yarn density of 180 warp threads/inch (70 warp threads/cm) and a weft yarn density of 130 warp threads/inch (51 warp threads/cm), whereby the resulting natural-colored fabric was subsequently relaxed at 95ºC and dyed at 130ºC.

Consequently, a high-density fabric with a warp density of 225 warp ends/inch (88 warp ends/cm) and a weft density of 156 warp ends/inch (61 warp ends/cm) was produced, which had fine loops developed on the surface and, furthermore, had a smooth surface finish and bulk similar to that obtained from super-long cotton fibers and had high-density stiffness.

Claims (29)

1. Crimped blended yarn, the surface of which has open and closed loops, whereby this crimped blended yarn at least one synthetic multifilament yarn component with a high shrinkage ratio and at least one synthetic multifilament component with a low shrinkage ratio, the shrinkage ratio of the filaments of the synthetic multifilament yarn component with a high shrinkage ratio in hot water is more than 10% and the difference in shrinkage ratio between that of the filaments of the synthetic multifilament yarn component with a high shrinkage ratio and that of the filaments of the synthetic multifilament yarn component with a low shrinkage ratio in hot water is more than 5%, wherein the crimped blended yarn is such that its total number and size of open and closed loops can be increased by thermal treatment of the yarn in the tension-free state, each loop is classified as a Class A, B or C loop in terms of its projection height, the number of loops above a given height being measured at a yarn speed of 50 m/min and a yarn tension of 0.1 g/d (0.0108 cN/tex), where Class A loops are loops that protrude above the yarn surface by more than 0.15 mm, Class B loops are loops that protrude above the yarn surface by more than 0.35 mm, and Class C loops are loops that protrude more than 0.6 mm above the yarn surface the crimped blended yarn on its surface before heat treatment more than 300 warp threads/m of class A loops, more than 50 warp threads/m of class B loops and has less than 10 warp threads/m of class C loops, the number of loops, measured after thermal treatment with hot water at 98ºC for 10 minutes in a tension-free state and subsequent drying, is such that at least the number of loops of class B is more than 1,5 times that of the crimped yarn before heat treatment, and the number of loops in class C is more than 50 warp threads/m. 2. Crimped blend yarn according to claim 1, which has been heat treated with hot water at 98ºC for 10 minutes in a tension-free state and then dried. 3. A crimped blended yarn according to claim 1 or 2, wherein a filament of the multifilament yarn component having a high shrinkage ratio has a denier of 0.1 - 15 denier (0.11 - 16.6 dtex) and a filament of the multifilament yarn component having a low shrinkage ratio has a denier of 0.05 - 1.3 denier (0.055 - 14.4 dtex). 4. A crimped blended yarn according to any one of claims 1 to 3, which has a shrinkage ratio of at least 10% in hot water. 5. A method of producing a crimped blended yarn in which at least first and second synthetic multifilament yarns are simultaneously fed to a texturing zone in which an eddy current flows, thereby producing a multifilament blended yarn having open and closed loops on its surface, which is then stretched, thereby eliminating or reducing the size of the open and closed loops, the first synthetic multifilament yarn having a shrinkage ratio in hot water higher than that of the second synthetic multifilament yarn. 6. The method of claim 5, wherein the first synthetic multifilament yarn has a shrinkage ratio in hot water of more than 10% and the difference between the respective shrinkage ratios of the first and second synthetic multifilament yarns in hot water is more than 5%. 7. The method of claim 5 or 6, wherein a filament of the second synthetic multifilament yarn has a denier of 0.05 - 1.3 denier (0.055 - 14.4 dtex). 8. A method according to any one of claims 5 to 7, wherein a filament of the first synthetic multifilament yarn has a denier of 0.1 - 15 denier (0.11 - 16.6 dtex). 9. The method of claim 7 or 8, wherein a sub-filament of the second synthetic multifilament yarn has a denier of 0.05 - 1.3 denier (0.055 - 14.4 dtex) and a sub-filament of the first synthetic multifilament yarn has a denier of 0.1 - 15 denier (0.11 - 16.6 dtex). 10. A method according to any one of claims 5 to 9, wherein the first and second multifilament yarns are fed to the texturing zone in an overdose, the respective advance ratio being different from one another. 11. The method of claim 10, wherein the second low shrinkage ratio multifilament yarn is fed to the texturing zone at a higher overfeed ratio than the overfeed ratio of the first high shrinkage multifilament yarn. 12. A method according to claim 11, wherein the first and second synthetic multifilament yarns are each treated in the texturing zone with compressed air which constitutes the eddy current, the first and second synthetic multifilament yarns simultaneously being fed to the texturing zone at an overfeed ratio λ of the first multifilament yarn of 2 - 15% and an overfeed ratio β of the second multifilament yarn of 5 - 30% and wherein the multifilament blend yarn thus treated is continuously stretched at a feed ratio of 0.4 λ - 0.8 λ and then wound onto a yarn carrier. 13. High density fabric that: (a) warp yarns comprising a mixed multifilament blend yarn having open and closed loops on its surface according to claim 1, wherein the cover factor (CF) of the warp yarns, given by the equation CF = n , where n is the yarn density (warp threads/inch) and d is the yarn denier or by the equation CF = 7.62 tex, where nSI is the yarn density (warp threads/cm), is more than 1100; and (b) Weft yarns includes. 14. A high density fabric according to claim 13, wherein the blended multifilament yarn comprises at least first and second synthetic multifilament yarn components, the first synthetic multifilament yarn component having a shrinkage ratio in hot water higher than that of the second multifilament yarn component. 15. The high density fabric of claim 14, wherein a filament of the second synthetic multifilament yarn component has a denier of 0.05 to 1.3 d (0.055 to 14.4 dtex) and a filament of the first synthetic multifilament yarn component has a denier of 0.1 to 15 d (0.11 to 16.6 dtex). 16. A high density fabric according to claim 15, wherein the first synthetic multifilament yarn component has a shrinkage ratio in hot water of more than 10% and the difference between the respective shrinkage ratios of the first and second multifilament yarn components in hot water is more than 5%. 17. A high density fabric according to any one of claims 13 to 16, which has been subjected to a heat treatment and wherein the number of loops above a given height is Yarn speed of 50 m/min and a yarn tension of 0,1 g/d (0,0108 cN/tex), the multifilament blended yarn has a number of loops C, which extend beyond the surface of the yarn by more than 0,6 mm, of at least 50 warp threads/cm. 18. A high density fabric according to any one of claims 13 to 17, comprising weft yarns of a synthetic multifilament yarn, each component filament of which has a flat cross-sectional shape and has a total coverage factor of the warp and weft yarns as defined in claim 13 of 1800 to 3500, the fabric having a spun-fiber-like feel. 19. A high density fabric according to claim 18, wherein the multifilament blended yarn has a shrinkage ratio of more than 10% in hot water. 20. A high-density fabric according to claim 18 or 19, wherein the flat ratio of each component filament of the synthetic multifilament yarn having the flat cross-sectional shape, which is the ratio of the side dimension to the width dimension, is 2.0 to 6.0. 21. A high-density fabric according to any one of claims 18 to 20, wherein the synthetic multifilament yarn whose component filament has a flat cross-sectional shape has a total shrinkage ratio of 8 to 27 in hot water, and wherein 30 to 70 wt% of the component filaments have a shrinkage ratio of 7 to 30% in hot water, and 70 to 30 wt% of the component filaments have a shrinkage ratio of 1 to 15% in hot water. 22. A mixed fabric with high density that (a) warp or weft yarns comprising mixed shrinkable multifilament yarns having open and closed loops on their surface and comprising at least one synthetic multifilament yarn according to claim 1; and (b) weft or warp yarns comprising spun yarns; includes, wherein the total coverage factor of its warp and weft yarns, as defined in claim 13, is 2000 to 3500. 23. A blended fabric according to claim 22, wherein the multifilament blended yarn has a shrinkage ratio of more than 10%. 24. A blended fabric according to claim 22 or 23, wherein the blended multifilament yarn comprises at least first and second synthetic multifilament yarns each having a different shrinkage ratio in hot water. 25. A blended fabric according to claim 24, wherein the shrinkage ratio of the first synthetic multifilament yarn component in hot water is higher than the shrinkage ratio of the second multifilament yarn component, the shrinkage ratio of the first synthetic multifilament yarn component in hot water is more than 10%, and the difference between the respective shrinkage ratios of the first and second multifilament yarn components in hot water is more than 5%. 26. A blended fabric according to claim 24 or 25, wherein a sub-filament of one multifilament yarn component has a denier of 0.1 to 2.5 d (0.011 to 0.28 tex) and a sub-filament of another multifilament yarn component has a denier of 0.3 to 15 d (0.033 to 1.67 tex). 27. A blended fabric according to any one of claims 22 to 26 which has been subjected to a heat treatment and wherein, the number of loops above a given height is measured at a yarn speed of 50 m/min and a yarn running tension of 0.1 g/d (0.0108 cN/tex), the multifilament blended yarn has a number of loops C rising more than 0.6 mm from the surface of the yarn of at least 50 warp ends/cm. 28. A blended fabric according to any one of claims 22 to 27, wherein the spun yarn has a cotton count of more than 30 S (less than 19.68 tex). 29. A method of making a woven fabric having a spun-like feel and resembling a fabric made from super-long cotton fibers, wherein the fabric is woven from blended multifilament blend yarns made from synthetic multifilament yarn components and having a total denier of less than 10 tex (90d), the blend yarn being made from a filament "a" having a shrinkage ratio in hot water of more than 12%, a denier of a component filament thereof being more than 0.17 tex (1.5d) and a total denier thereof being less than 6.67 tex (60d), and a filament "b" having a shrinkage ratio in hot water of less than 10%, a denier of a component filament thereof being less than 0.11 tex (1.0d), and total denier of which is less than 6.67 tex (60d), the blended yarn being further characterized in that it has, prior to shrinkage, more than 300 warp ends/m of loops A, more than 50 warp ends/m of loops B and less than 10 warp ends/m of loops C, each loop A, loop B and loop C being defined below, wherein after weaving, shrinking of the fabric is carried out to cause a differential shrinkage between filament "a" and filament "b" resulting in the protrusion of the open and closed loops of filament "b" on the surface of the fabric, each loop A, loop B and loop C being defined in such a way that, each loop is spun at a yarn speed of 50 m/min and a yarn running tension of 0.1 g/d (0.0108 cN/tex) measured with a photoelectric fuzz measuring device by which the number of loops of a yarn passed through is counted, a loop which projects beyond the yarn surface by more than 0.15 mm is referred to as loop A, a loop which projects beyond the yarn surface by more than 0.35 mm is referred to as loop B, and a loop which projects beyond the yarn surface by more than 0.6 mm is referred to as loop C.